Snow continued to fall on the East Coast this morning, another burst from a storm that slammed the region with heavy snow, freezing rain and sleet Thursday.

At least 21 deaths – most of them in traffic accidents – were blamed on the storm as it made its way across the South and up the coast. The victims include a pregnant New York City woman who was struck by a snow plow and killed. Her baby was delivered by cesarean section.

Snow totals included 12 inches in Baltimore; 11 inches in Philadelphia and New York City; and 15 inches in parts of New Jersey.

Some areas in Virginia experienced 28 inches of snow.

The snow and ice caused building roofs to collapse, including a tennis center on Long Island, a Virginia gas station and numerous homes in New Jersey.

It's a Snow Brainer: Make It Stop

Additionally, a Spirit Airlines flight was struck by lightning while landing in Atlantic City, N.J.

The storm's changing precipitation – from heavy snow to pounding rain and back to snow – left roadways flooded and covered in a soupy slush. The travel problems extend to air travel, with thousands of flights canceled across the country, according to the website FlightAware.com. In Washington, D.C., the two main airports were closed. Amtrak canceled and delayed train service.

Philadelphia mayor Michael Nutter called on residents to help one another, encouraging teens to build their college funds in the process.

"To the young people of Philadelphia, given that you have a day off, grab a shovel," Nutter said. "There is much money to be made."

The ongoing weather problems have left states depleted. Gov. Daniel Malloy said Connecticut is declaring a state of emergency because of low salt supplies.

"We will be asking the White House and FEMA to assist us in locating additional stocks of salt for the purposes of building up our supply beyond a one-storm supply," Malloy said.

"Under normal conditions that would be fine, but we're being told by the salt suppliers that they are not ... They're not locating additional salt, so that's the problem."

Those salt supplies will likely diminish in the coming days. While today's temperatures could reach 40 degrees in many areas, leading to melting, more snow is expected this weekend across the Northeast.

Major cities are expected to get 1 to 3 inches, but some areas in New England could experience another doozy, with 6 to 10 inches possible.

By next week, highs should climb into the 50s.

But that is still days – and at least one more storm – away for an East Coast that's running low on winter patience.

ABC News' Max Golembo, ABC News Radio and The Associated Press contributed to this report.